58 lines
1.5 KiB
C++
58 lines
1.5 KiB
C++
/*
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LEDC Software Fade
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This example shows how to software fade LED
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using the ledcWrite function.
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Code adapted from original Arduino Fade example:
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https://www.arduino.cc/en/Tutorial/Fade
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This example code is in the public domain.
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*/
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// use first channel of 16 channels (started from zero)
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#define LEDC_CHANNEL_0 0
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// use 12 bit precission for LEDC timer
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#define LEDC_TIMER_12_BIT 12
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// use 5000 Hz as a LEDC base frequency
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#define LEDC_BASE_FREQ 5000
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// fade LED PIN (replace with LED_BUILTIN constant for built-in LED)
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#define LED_PIN 5
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int brightness = 0; // how bright the LED is
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int fadeAmount = 5; // how many points to fade the LED by
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// Arduino like analogWrite
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// value has to be between 0 and valueMax
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void ledcAnalogWrite(uint8_t channel, uint32_t value, uint32_t valueMax = 255) {
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// calculate duty, 4095 from 2 ^ 12 - 1
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uint32_t duty = (4095 / valueMax) * min(value, valueMax);
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// write duty to LEDC
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ledcWrite(channel, duty);
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}
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void setup() {
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// Setup timer and attach timer to a led pin
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ledcSetup(LEDC_CHANNEL_0, LEDC_BASE_FREQ, LEDC_TIMER_12_BIT);
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ledcAttachPin(LED_PIN, LEDC_CHANNEL_0);
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}
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void loop() {
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// set the brightness on LEDC channel 0
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ledcAnalogWrite(LEDC_CHANNEL_0, brightness);
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// change the brightness for next time through the loop:
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brightness = brightness + fadeAmount;
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// reverse the direction of the fading at the ends of the fade:
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if (brightness <= 0 || brightness >= 255) {
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fadeAmount = -fadeAmount;
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}
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// wait for 30 milliseconds to see the dimming effect
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delay(30);
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}
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